Andrew Ozz

Shutter Reloaded is an image viewer for your website that works similarly to Lightbox, Thickbox, etc. but is under 10KB in size and does not require any external libraries. It has many features: resizing large images if the window is too small to display them with option to show the full size image, combining images in sets, redrawing the window after resizing, pre-loading of neighbour images for faster display and very good browser compatibility.
This plugin offers customization of the colour and opacity settings for the background and colour for the caption text, buttons text and the menu background.
There are options to enable it for all links pointing to an image on your site (with option to exclude some pages), or just on selected pages. It can be enabled only for image links with CSS class=”shutter” with option to create a single set or multiple sets for each page.
The plugin can also “auto-make” image sets for each Post, so when several posts are displayed on the “Home” page, links to images on each post will be in a separate set. See the built-in help for more information.

Shutter Reloaded

Darkens the current page and displays an image (like Lightbox, Thickbox, etc.), but is a lot smaller (10KB) and faster.

Whodunit

Jb Audras

A simple, responsive and 100% free Gutenberg Block to display PDF Viewers / Readers on your website.
You can easily configure the Reader’s width, height and alignment on the fly.
Compatibility: 
– Fully responsive 
– Works fine on Chrome, Firefox, Opera, Edge and IE11 
– If javascript is disabled, a download link is provided as a fallback
This plugin uses <a href="https://mozilla.github.io/pdf.js/" rel="nofollow ugc">PDF.js</a> library, provided by Mozilla under Apache license.

PDF Viewer Block for Gutenberg

Very easy to install and to use. No need to configure anything.
And it works out of the box.

The best PDF Viewer

A simple and 100% free Gutenberg Block to display PDF Viewers / Readers on your website.

Shutter Reloaded vs PDF Viewer Block for Gutenberg